NEDD4L-Induced Ubiquitination Mediated UBE2T Degradation Inhibits Progression of Lung Adenocarcinoma Via PI3K-AKT Signaling

Abstract Background: Accumulating studies have indicated that Ubiquitin-conjugating enzyme E2T (UBE2T), as an oncogene, promotes progression and metastasis of lung cancer, including lung adenocarcinoma (LUAD), but it is completely unknown whether and how UBE2T is ubiquitylated and degraded, and by which E3 ligase. Methods: The relationship NEDD4L with UBE2T in LUAD tissues and cells was found by bioinformatic analyses and immunoblotting. Cell counting kit-8, colony formation assay, half-life analysis and the in vivo ubiquitylation assay, generation of xenograft model were performed to determine how NEDD4L regulates UBE2T and its downstream signaling pathway in vitro and in vivo.Results: Bioinformatic analyses found that NEDD4L, as a potential correlation E3 ligase of UBE2T, was negatively correlated with UBE2T in LUAD. Consistently, UBE2T protein half-life was shortened or extended by NEDD4L overexpression or depletion, respectively. NEDD4L against LUAD cell progression in vitro and in vivo via inducing the ubiquitination-mediated UBE2T degradation, which repressed PI3K-AKT signaling. Similarly, NEDD4L predicted a better patient survival, whereas UBE2T predicted a worse survival.Conclusions: Collectively, our study reveals that NEDD4L is a novel E3 ligase of UBE2T for targeted ubiquitination and degradation, and results in repressing PI3K-AKT signaling, which can inhibit LUAD cell progression.